Yes I remember Randucci doing those .... the material is some sort of stable matting used on competition blades ....
If you wanted the grip comfort of Res C without disturbing the balance point of the blade then going down this route would work.
My enjoyment of the Res C knives though comes a lot from the weight saving in the Knife ..... the hidden tang which when balanced with the right blade gives a weighted forward feel to the knife enabling chopping ability to be the same as heavier blades with a full tang ....
For me Res C blades maximise the performance to weight side of things as well as being very comfortable ...